Under certain operating conditions, undesirable condensation can occur on the outside surface of freezer/refrigeration equipment. The condition may exist when the freezer/refrigeration equipment having a lower internal temperature is operated in an ambient environment of elevated temperature and elevated relative humidity. The outside surface of the freezer/refrigeration equipment generally remains cold and the air film about the surface is also cold. Since cold air can not contain as much moisture as warm air, it separates out and settles in a liquid phase on the cold surface(s). Once the phase change occurs, from vapor to liquid, changing the liquid back to vapor generally takes a long time due to additional energy requirements necessary to achieve a phase change.
The result of the phase chance, from vapor to liquid, on a freezer/refrigeration surface may be many fold. For instance, condensation may run down from the freezer/refrigeration surface to the floor area and collect to produce a puddle.
Freezer/refrigeration equipment may generally use gasket materials to seal an internal compartment. This compartment may contain specimens which require being subjected to certain operating temperatures for one of a variety of reasons. For example, it may be important to maintain the operating temperature of a specimen in order to preserve the specimen in a prescribed manner or to ensure that it doesn't spoil. Another reason may be to develop cultures within a prescribed operating temperature environment. This operating temperature may be further important for developing the culture at an optimum growth rate for example.
Should condensation develop and/or refreeze along any freezer/refrigeration sealing areas such as a gasket, the gasket may lose its ability to remain flexible in order to seal surfaces completely. Hence, with a seal unable to conform to the surface of the freezer/refrigeration equipment, potential air paths could develop along the gasket surface contact area. This effect could result in the freezer/refrigeration equipment not being able to seal properly and hence, an inability of the freezer/refrigeration equipment to maintain a prescribed operating temperature(s). Thus, a loss of energy and time may result in attempting to generate and maintain an operating temperature of the freezer/refrigeration equipment. Additionally, when the aforementioned gasket looses its flexibility as described, the integrity of the sealing capacity of the inner chamber has the potential to become compromised, and the specimen(s) may become contaminated due to the freezer/refrigeration equipment not being able to maintain a prescribed operating temperature.
Traditional freezer/refrigeration systems may attempt to prevent and/or combat undesirable condensation effects by introducing a supplemental heat source to a back side of a surface likely to form condensation. Traditionally, the heat source can be hot gas routed from the refrigeration system, electrical resistance heaters, or the like. This arrangement is typically configured to provide continuous heating to the freezer/refrigeration system.
However, in practical application, additional heat is often only necessary under certain conditions to prevent the formation of condensation, such as, when the freezer/refrigeration equipment has a lower internal temperature and is operated in an ambient environment of elevated temperature and elevated relative humidity. However, the aforementioned traditional arrangement generally requires the freezer/refrigeration arrangement to continuously overcome the constant supplemental supply of heating in an attempt to prevent condensation from forming on the surface. This kind of set-up is not necessarily the most efficient way to control condensation on freezer/refrigeration surfaces, since additional heat is generally only necessary under certain prescribed conditions. Thus, providing a continuously supply of supplemental heat, without taking into account the operating environment of the freezer/refrigeration equipment, can waste unnecessary energy and drive up the operating/maintenance costs of the freezer/refrigeration system.
Accordingly, it is desirable to provide a method and apparatus that provides supplemental heat from a heat source based upon the operating environment of the freezer/refrigeration equipment. It is further desirable to provide automatic control of the supplemental heat provided to the freezer/refrigeration equipment. It is also desirable to automatically control the operation of providing supplemental heat such that it is only activated under conditions that would promote surface condensation on the sealing surface of freezer/refrigeration equipment.